Analog Discovery 2

[mnorth]

I just received my AD2 and am running the python examples from the SDK directory.
Looking at the forum this feels like a very silly question.  I've got a scope hooked up to DIO 0 and I can't see
any analog signals like from example: AnalogOut_sine.py or AnalogIn_Record.py.  
I've notice the numpy plts, maybe that's the hint that I can't use the scope to view analog output?

[attila]

Hi @mnorth

The AnalogOut_sin.py generates signal on W1 and the AnalogIn_Record.py streams data from scope input 1+/-

[mnorth]

Thanks Atilla.  a few more elementary sounding questions.  I wanted to see if I could input something analog trying to use say, AnalogIn_Sample.py...
I just connected V+ supply to DIO0 and then 1+...my DMM read ~58mV-ish...the results that printed out weren't good.
I looked around for setting the supply power and found: AnalogIO_AnalogDiscovery2_Power.py 
FDwfAnalogIOChannelNodeSet(hdwf,idxChannel, idxNode, value)
# enable positive supply
dwf.FDwfAnalogIOChannelNodeSet(hdwf, c_int(0), c_int(0), c_double(True)) 
# set voltage to 5 V
dwf.FDwfAnalogIOChannelNodeSet(hdwf, c_int(0), c_int(1), c_double(5.0)) 

1) I don't measure anything out of V+ and nothing from channel 0.
2) I've been reading the API.  What exactly is a "Node Index" ?  Is that to distinquish between an enable and a set value?
3) So, back to AnalogIn_Sample.py...I don't have a function generator...use an old 10k pot as an input to 1+ ??

[attila]

Hi @mnorth

Did you set the master enable? as it is AnalogIO_AnalogDiscovery2_Power.py
By default on app/script exit or device close function the outputs are stopped (disabled). Keep the app/running or set the onclose to run.

# master enable
dwf.FDwfAnalogIOEnableSet(hdwf, c_int(True))

# 0 = run, 1 = stop, 2 = shutdown
dwf.FDwfParamSet(DwfParamOnClose, c_int(0))

[mnorth]

Thanks Atilla. 
I am fiddling with a trigger idea using python and have been using example: AnalogIn_Record.py.
I'm sending an analog input signal to Scope 1+ and am successfully writing it to the csv file.  
I followed DigitalOut_custom example and in the same trigger code produced a signal with a period of 2usec with the first 500nsec high, on DIO1.  
I am hoping to write a trigger for the falling edge of this DigitalOut signal and to only capture say n samples per falling edge.
Can we trigger on a digitalOut signal and acquire data from the analogIn?
If so, is there an example (I have looked...I could have missed it)?  If not, that's interesting...do you have a suggestion?

 

[mnorth]

I may have figured this particular trigger question out ...it appears to be the subtle difference between, trigsrcDetectorDigitalIn and trigsrcDigitalIn.

[attila]

Hi @mnorth

The AnalogIn could be triggered on the DigitalOut start or each period/restart if you are using finite run:
dwf.FDwfDigitalOutRunSet(hdwf, c_double(cSamples/hzRate))
dwf.FDwfAnalogInTriggerSourceSet(hdwf, trigsrcDigitalOut) 

Trigger on DIO1 could be done using the DigitalIn trigger detector but it is easier to hook the DIO1 to T1 and trigger AnalogIn on this.
dwf.FDwfAnalogInTriggerSourceSet(hdwf, trigsrcExternal1) 
dwf.FDwfAnalogInTriggerConditionSet(hdwf, DwfTriggerSlopeFall) 

[mnorth]

Thanks Atilla. I'm sending an analog input to Scope 1+.  I followed DigitalOut_custom example and in the same trigger code produced a
2usec digitalOut signal with the first 500nsec high, on DIO1.  Wanting to write a trigger for the falling edge of this DigitalOut signal and
only capture say n samples per falling edge of 100-ish cycles.
I'm not sure about the AcqFrqHz ideas...could you give me some ideas about how to choose those numbers?
Obviouly, change anything...

100 cycles: c_psecRun = 0.2 sec

pattern_repeat = 100                    # fixed number
nSamples = ???

AcqFrqHz = c_double(???) 

# SETUP AnalogIn ACQUISITION
dwf.FDwfAnalogInChannelEnableSet(hdwf, c_int(0), c_bool(True))
dwf.FDwfAnalogInAcquisitionModeSet(hdwf, acqmodeRecord) 
dwf.FDwfAnalogInFrequencySet(hdwf, AcqFrqHz) 

### RecordLength is in sec.  Would record time be the same as c_psecRun ?                                                                                          
dwf.FDwfAnalogInRecordLengthSet(hdwf, c_double(nSamples/AcqFrqHz.value))

# SETUP TRIGGER on DOut_1:
dwf.FDwfAnalogInTriggerSourceSet(hdwf, trigsrcDetectorDigitalIn)                            
dwf.FDwfDigitalInTriggerSet(hdwf, c_int(0), c_int(0), c_int(0), c_int(1<<1))    
 
### Is (???), nSamples/pattern_repeat ?                  
dwf.FDwfDigitalInTriggerPositionSet(hdwf, c_int(int( ??? )))                                              
dwf.FDwfDigitalInTriggerCountSet(hdwf, c_int(1), c_int(0))                     

time.sleep(1)

dwf.FDwfAnalogInConfigure(hdwf, c_int(1), c_int(1))
dwf.FDwfDigitalOutConfigure(hdwf, c_int(1))  

[attila]

Hi @mnorth

The record mode is intended for long captures, streaming samples and the frequency can be up to about 1-2MHz.
If you want to capture only up to 8/16Ki samples you can use the normal (single) capture mode at up to 100MHz.

Edited June 10, 2022 by attila